In my previous application entitled METHOD AND APPARATUS FOR GENERATING A NEGATIVE CHARGE EFFECT IN AN ENVIRONMENT, Ser. No. 557,869, filed Mar. 12, 1975, now U.S. Pat. No. 4,037,268, I have disclosed a method and apparatus for producing electrons that give a negative charge to surrounding materials such as air, dust, etc. While the device described in that patent works very satisfactorily, it had the disadvantage that air passing between the open plates would deposit dirt on them, impairing their efficiency and requiring cleaning. Also, if the device were operated improperly, ozone could be generated, an undesirable situation.